The triangle bounded by the lines y = o, y = 2x and y = -0.5x + k with k positive is equal to 80 square untits find k

Yesterday i ran 5 miles. today, i ran 3.7 miles. did my percent increase, decrease or is it a percent error? plz i need

If mary had 320 toy cars and she gave her friend 50 cars and then she gave her brother 72 more cars how much toy cars would mary have left ● explain with proper details

Either enter an exact answer in terms of \piπ or use 3.143.14 for \piπ and enter your answer as a decimal.